HttpCacheSM should not be checking redirection retries

In HttpCacheSM.cc:

   336    if (open_write_tries > master_sm->redirection_tries &&
   337        open_write_tries > master_sm->t_state.txn_conf->max_cache_open_write_retries) {
   338      master_sm->handleEvent(CACHE_EVENT_OPEN_WRITE_FAILED, (void *)-ECACHE_DOC_BUSY);
   339      return ACTION_RESULT_DONE;
   340    }

First, you are not supposed check ``redirection_retries`` without first checking ``enable_redirection``. Second, redirection retries should be handled above this layer; it seems really hokey to have this check smuggled into the HTTP cache layer. Presumably if the HTTP state machine has already decided to retry a redirect we should not be second guessing that.